qemu-patch-raspberry4/target/openrisc/interrupt.c
Stafford Horne 9f6e8afad7 target/openrisc: Fix delay slot exception flag to match spec
The delay slot exception flag is only set on the SR register during
exception.  Previously it was being set on both the ESR and SR this
caused QEMU to differ from the spec.  The was apparent as the linux
kernel had a bug where it could boot on QEMU but not on real hardware.

The fixed logic now matches hardware.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Stafford Horne <shorne@gmail.com>
2018-07-03 22:40:33 +09:00

124 lines
3.7 KiB
C

/*
* OpenRISC interrupt.
*
* Copyright (c) 2011-2012 Jia Liu <proljc@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "exec/exec-all.h"
#include "qemu-common.h"
#include "exec/gdbstub.h"
#include "qemu/host-utils.h"
#ifndef CONFIG_USER_ONLY
#include "hw/loader.h"
#endif
void openrisc_cpu_do_interrupt(CPUState *cs)
{
#ifndef CONFIG_USER_ONLY
OpenRISCCPU *cpu = OPENRISC_CPU(cs);
CPUOpenRISCState *env = &cpu->env;
int exception = cs->exception_index;
env->epcr = env->pc;
if (exception == EXCP_SYSCALL) {
env->epcr += 4;
}
/* When we have an illegal instruction the error effective address
shall be set to the illegal instruction address. */
if (exception == EXCP_ILLEGAL) {
env->eear = env->pc;
}
/* During exceptions esr is populared with the pre-exception sr. */
env->esr = cpu_get_sr(env);
/* In parallel sr is updated to disable mmu, interrupts, timers and
set the delay slot exception flag. */
env->sr &= ~SR_DME;
env->sr &= ~SR_IME;
env->sr |= SR_SM;
env->sr &= ~SR_IEE;
env->sr &= ~SR_TEE;
env->pmr &= ~PMR_DME;
env->pmr &= ~PMR_SME;
env->lock_addr = -1;
/* Set/clear dsx to indicate if we are in a delay slot exception. */
if (env->dflag) {
env->dflag = 0;
env->sr |= SR_DSX;
env->epcr -= 4;
} else {
env->sr &= ~SR_DSX;
}
if (exception > 0 && exception < EXCP_NR) {
static const char * const int_name[EXCP_NR] = {
[EXCP_RESET] = "RESET",
[EXCP_BUSERR] = "BUSERR (bus error)",
[EXCP_DPF] = "DFP (data protection fault)",
[EXCP_IPF] = "IPF (code protection fault)",
[EXCP_TICK] = "TICK (timer interrupt)",
[EXCP_ALIGN] = "ALIGN",
[EXCP_ILLEGAL] = "ILLEGAL",
[EXCP_INT] = "INT (device interrupt)",
[EXCP_DTLBMISS] = "DTLBMISS (data tlb miss)",
[EXCP_ITLBMISS] = "ITLBMISS (code tlb miss)",
[EXCP_RANGE] = "RANGE",
[EXCP_SYSCALL] = "SYSCALL",
[EXCP_FPE] = "FPE",
[EXCP_TRAP] = "TRAP",
};
qemu_log_mask(CPU_LOG_INT, "INT: %s\n", int_name[exception]);
hwaddr vect_pc = exception << 8;
if (env->cpucfgr & CPUCFGR_EVBARP) {
vect_pc |= env->evbar;
}
if (env->sr & SR_EPH) {
vect_pc |= 0xf0000000;
}
env->pc = vect_pc;
} else {
cpu_abort(cs, "Unhandled exception 0x%x\n", exception);
}
#endif
cs->exception_index = -1;
}
bool openrisc_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
{
OpenRISCCPU *cpu = OPENRISC_CPU(cs);
CPUOpenRISCState *env = &cpu->env;
int idx = -1;
if ((interrupt_request & CPU_INTERRUPT_HARD) && (env->sr & SR_IEE)) {
idx = EXCP_INT;
}
if ((interrupt_request & CPU_INTERRUPT_TIMER) && (env->sr & SR_TEE)) {
idx = EXCP_TICK;
}
if (idx >= 0) {
cs->exception_index = idx;
openrisc_cpu_do_interrupt(cs);
return true;
}
return false;
}